Lathe attachment.



J. SOHULTZE.

LATER ATTACHMENT.

APPLICATION FILED FEBJ, 1910.

Patented July 25, 1911.

WIT/VESSES MMM/m UNITED sTATEs PATENT OFFICE.

vJOHN SCHIULTZE, OF OOPER, TEXAS.

I To all whom it mwyconcern:

Be it known that I, JOHN SOHULTZE, citiyzen of the United States, residing at Cooper,

in the county of Deltav and State of Texas,

have invented certain new and useful `Immore particular to that class of lathe attachments used ,by jewelers for holdingA fragile articles to be turned.

The object of my invention is to provide a device of the character described which will be easy to vattach to any lathe and one which will hold an article to be turned without scratching its surface.

Another object of my invention is to provide a device of the character described of a watch so that thevedge may be ground down. and one which will protect the face of the crystal while it, is being ound.

Finally the object of the invention is to provide means of the character deribed easy of operation, simple and comparatively inexpensive to construct, and also in which the several parts. will not be likely to get out of working order.

90 With the Iabove and other objects in view,

. the invention has relation to certain novelface-2, and an enlarged portion 3. A mandrel 4 extends rearwardly from the portion 3 and is held against rotation by a squared portion 5 which engages with a sleeve 6 held in the portion 3. It i's apparent that 1f the squared portion 5 and sleeve 6 were not provided and the surface of the mandrel being smooth, said mandrel might have a tendency to turn or revolve 1n the cap as only the frictional engagement of the resilient material with mandrel would be relied upon to fasten the parts together. By providing which can be used for holding the crystal that will be strong, durable, efficient, and

Specification of Letters' Patent. Patented J 11157 257 1911. Application Ied February 1, 1910. Serial No. 541,238;

the sleeve, any rocking or turning movement of the mandrel in the cap is. checked by the sleeve. If the sleeve was not provided a slight movement of the mandrel would in time wear theresilient material until the mandrel would be free to turn. While the sleeve may be omitted it is a desirable element. This mandrel is held against'lateral movement` by a head 7 embedded in the enlarged portion.

In Fig. 3 I have shown-my suction cap attached to a watch crystal ready for insert-y y ing the mandrel in the chuck of an ordinary lathe so that the crystal may be ground down. It is often necessary to grind'a crystal and make it smaller in order to get the same't'o fit the bezel. The `common method ofl attaching these crystals to a lathe, has been long and tedious as the crystal is first glued to a piece' of wood and allowed to dry, then thev wood is fastened to a face by means of screws. After the crystal has been ground dowir it is necessary to wash the crystal in order to remove the glue or adhesive material from its face. To u'se'the suction cap for att-aching these crystals to a lathe it is only necessary vto place the cap over the crystal and to press the two together until the air beneath the cap has been exhausted. When this is done the spaces 8 as shown in Fig. 3 will be sealed by the con-A tacting portions of the suction cap forming A vacuum strong enough to hold the cap and crystal together. lThe mandrel mayithen be inserted in the Ychuck of a lathe and the size of a crystal maybe reduced, by holding a piece of emery paperagainst the edge ofthe crystal. Should the crystal show a tendency of Working loose it is only necessaryl to remove the same and slightly .moisten it and then replace'it where it will be held more firmly. than before.`

It is obvious that this suction cap may be used to fix other articles of manufacture in a position to be able tool.

What I claim is: f

I ground or scraped by a suitl. A lathel chuck comprising a body hof circular body of resilient material having a dishedv face and provided with a solid central and rearwardly extending boss, a metallic mandrel having a head and a flattened portion adjacent the head, and a sleeve surrounding the flattened portion of the mandrel, the sleeve and the head of the mandrel being embedded against rotation in the boss.

3. In a lathe chuck for watch crystals, a circular body of resilient material having a dished face, a boss extending rearward from the central rear side of the body, Said boss protruding a considerable distance from the head, and a mandrel having an enlarged head and a squared portion extending from the head, the head and squared portion being embedded in the boss.

In testimony whereof I'have signed my name to this specification in the presence of two subscribing witnesses.

JOHN SCHULTZE.

Witnesses:

JACK A. SCHLEY, L. E. NoAoK. 

